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Abstract

Background

This study aimed to examine differences in socio-demographics and health behaviour
between Belgian first year university students who attended all final course exams
and those who did not. Secondly, this study aimed to identify weight and health behaviour
related correlates of academic performance in those students who attended all course
exams.

Methods

Anthropometrics of 101 first year university students were measured at both the beginning
of the first (T1) and second (T2) semester of the academic year. An on-line health
behaviour questionnaire was filled out at T2. As a measure of academic performance
student end-of-year Grade Point Averages (GPA) were obtained from the university’s
registration office. Independent samples t-tests and chi2-tests were executed to compare students who attended all course exams during the
first year of university and students who did not carry through. Uni- and multivariate
linear regression analyses were conducted to identify correlates of academic performance
in students who attended all course exams during the first year of university.

Results

Students who did not attend all course exams were predominantly male, showed higher
increases in waist circumference during the first semester and consumed more French
fries than those who attended all final course exams. Being male, lower secondary
school grades, increases in weight, Body Mass Index and waist circumference over the
first semester, more gaming on weekdays, being on a diet, eating at the student restaurant
more frequently, higher soda and French fries consumption, and higher frequency of
alcohol use predicted lower GPA’s in first year university students. When controlled
for each other, being on a diet and higher frequency of alcohol use remained significant
in the multivariate regression model, with frequency of alcohol use being the strongest
correlate of GPA.

Conclusions

This study, conducted in Belgian first year university students, showed that academic
performance is associated with a wide range of weight and health related behaviours.
Future studies should investigate whether interventions aiming at promoting healthy
behaviours among students could also have a positive impact on academic performance.

Keywords:

Weight; Health behaviour; Correlates; Academic performance; First year university students

Background

Higher academic performance during the years at university is highly related to career
success [1]. Moreover, academic performance influences future educational attainment and income,
which, in turn, affect health and quality of life [1,2]. Therefore, determining factors related with academic grades is important to both
universities [3] and their undergraduates.

Some authors indicated that secondary school average was the strongest positive predictor
of academic performance in both male and female university students [4-6]. Furthermore, different studies agreed that female university students tended to
have greater academic success [3,6,7]. In a study of Singleton et al. [5] in US college students parental education as well as ethnicity (being Caucasian)
correlated positively with academic performance. Although students living in a student
residence are assumed to experience less parental control, which might influence academic
efforts and achievement negatively, no previous studies investigated the role of residency
(on or off campus) on academic performance in university students.

It has been shown in literature that physical activity participation as well as more
healthy diets (i.e. diets low in saturated fats and refined sugars) are beneficial
to cognition [8,9], suggesting that health behaviours may affect cognitive performances. University,
and especially the freshman year, is a period in which students are often subject
to several health behaviour related and lifestyle changes [10-12]. Hence, Grade Point Averages (GPA), which is often used as a measure for academic
performance, might be affected by such health behaviour changes during the first year
at university. Although studies in secondary school students have shown associations
between several health behaviours (physical activity, sedentary lifestyle and diet)
and academic performance [13-15], literature relating health behaviour to academic performance in university students
is scarce and limited to US studies. A recent study revealed that university students
who engaged in strength exercise more frequently had significantly higher GPA’s [16]. Regarding the relation between sedentary behaviour and academic performance, playing
videogames was found to be negatively related to GPA [17]. No relationships between other sedentary activities (e.g. TV watching, reading and
studying, computer activities) and academic performance in university students have
been examined so far. In a study in first year university students, Trockel et al.
[3] only found a positive relation with frequency of eating breakfast, whereas no other
diet-related variables (e.g. fruit and vegetable intake) were significantly related
to academic performance. Several authors found a negative correlation between alcohol
consumption and academic performance [5,6,18]. Smoking was also negatively related to GPA [6]. Furthermore, the review study of Curcio et al. [19], conducted in all student age categories, showed a clear negative relation between
sleep quality and quantity, and student learning capacity and academic performance.
However, other work did not find a significant correlation between total sleep time
and academic achievement [20]. Finally, the review by Richardson et al. [21] indicated that stress was negatively related to academic achievement. To the best
of our knowledge no studies have assessed the association between dieting status or
body composition and academic performance in university students.

In summary, only a limited number of studies (mostly conducted in the US) examined
the relationship between end-of-year performance and certain health behaviours (e.g.
physical activity, dietary behaviour) in university students, while relations with
other health behaviours (e.g. dieting status) and body composition have not been studied
yet. Due to socio-cultural differences we cannot extrapolate these US findings to
European university students. Hence, next to what is known from previous US studies,
this manuscript should provide complementary European evidence on how weight, socio-demographics
and health related behaviours relate to academic performance in this population. Therefore,
the first purpose of this study was to examine differences in socio-demographics and
health behaviour between Belgian (European) first year university students who attended
all course exams and received a GPA (and either passed or failed) and those who quit
university or did not carry through all exams and therefore did not receive a GPA.
The second purpose of this study was to investigate a wide range of weight and health
behaviour related correlates of academic performance in those students who attended
all course exams during the first year of university and therefore received a GPA.

Methods

Participants

Convenience sampling (via e-mail and face-to-face recruitment) was used to recruit
Belgian first year university students at the Vrije Universiteit Brussel. Hundred
and one participants were prepared to participate and completed all anthropometric
measurements and a health behaviour questionnaire. Since self-reported data of all
first year university students (=924) were obtained during enrolment (by the university’s
registration office), we were able to verify the representativeness of the sample.
The study sample (21.8 ± 2.8 kg/m2) was representative in comparison to all freshmen in Body Mass Index (BMI) (21.4 ± 2.8 kg/m2, t = -1.1; p = 0.262), but was slightly younger (18.0 ± 0.7 yrs; 18.5 ± 1.1 yrs, t = 5.6; p < 0.001) and consisted of a higher proportion of female participants (67.3% versus
56.6% females, chi2 = 4.3; p = 0.039).

Procedure

Anthropometric measurements were conducted at both the beginning of the first and
second semester of the academic year (October/November 2011 (T1) and February/March
2012 (T2)). The on-line questionnaire was only filled out at T2. All anthropometric
tests were conducted in the anthropometrics laboratory at the Faculty of Physical
Education and Physiotherapy, whereas the on-line questionnaire could be filled out
at home. To minimize possible effects due to sudden short-term lifestyle changes after
holiday periods, measurements were conducted after two weeks of academic activities.
At both time points students received an incentive (a lunch voucher). An informed
consent was signed by all participants before the start of the study. The study protocol
was approved by the medical ethical committee of the university hospital. More detailed
methodological information can be found elsewhere [12].

Measurements

Anthropometrics

At both time points, all students were measured with bare feet, wearing light sports
clothing (shorts and t-shirt). They were asked to void their bladder before starting
the measurements as well as to remove all jewellery. Weight (TANITA BC-418 MA Body
Composition Analyzer) and height (wall-fixed stadiometer) were measured to calculate
BMI. Fat% (TANITA for bio-electrical impedance analysis) and waist circumference (WC)
(measured with Rosscraft Anthrotape on the narrowest part of the waist) were measured
to analyse body composition and fat distribution. All measurements, except those using
TANITA, were conducted twice and an additional third time when tolerance limits were
exceeded. Subsequently, mean values were calculated from the two nearest values.

Health behaviour questionnaire

At T2 all participants were also asked to complete a self-reported on-line questionnaire
assessing demographics, socio-economic status, smoking, dieting status, physical activity,
sedentary behaviour, dietary habits, sleeping habits and mental stress. These behaviours
were assessed as literature demonstrated their potential contribution to academic
performance in secondary school or college/university students [3,15,18,22]. The questionnaire consisted of questions derived from existing questionnaires (Project
EAT-II Survey for Young Adults [23], Health Behaviour in School-aged Children (HBSC) [24], Health and Behaviour Survey (HBS) [25], Flemish Physical Activity Questionnaire (FPAQ) [26], Perceived Stress Scale (PSS) [27]). All items included in the questionnaire as well as reference to the original questionnaire
can be found in Table 1.

Table 1.Descriptive statistics of possible influencing factors of GPA in first year university
students (%, Mean ± SD, n = 101), subdivided into students who passed (n = 52), failed
(n = 22) or did not attend all final course exams (n = 27)

GPA

Finally, after the end of the academic year GPA’s (in%) of students who attended all
course exams were obtained from the university’s registration office as a measure
of academic performance.

Data analyses

SPSS Statistics 20 was used for data analyses. Independent samples t-tests and chi2-tests were executed to compare students who attended all course exams during the
first year of university and students who did not carry through. A multiple linear
regression analysis was conducted to identify correlates of academic performance in
students who attended all course exams during the first year of university. Before
running the multiple regression analysis, GPA was regressed onto each demographic
variable and health behaviour measured at T2, all initial anthropometric variables
at T1, as well as anthropometric changes over time (T2-T1). After checking for multicollinearity
(r > 0.5) only significant correlates of GPA were included into the multiple regression
analysis. p-Values < 0.05 were considered as statistically significant, whereas p-values < 0.1 were considered as trends towards significance.

Results

Comparison of characteristics and health related behaviour between students who attended
all course exams during the first year of university and those who did not carry through

Of the 101 participants, 51.5% passed (n = 52) and 21.8% failed (n = 22) their final
exams, whereas 26.7% either quit university, or did not attend all course exams and
therefore did not receive a final GPA. Before examining correlates of GPA, a comparison
between students who attended all final course exams (n = 74) and those who did not
(n = 27) was made to assess possible differences in student socio-demographics and
health related behaviours (shown in Table 1). Students who attended all course exams and students who did not showed a similar
BMI at baseline (21.7 ± 2.7 kg/m2; 21.1 ± 3.3 kg/m2; t = 0.6, p = 0.535). Mean age (18.0 ± 0.6 yrs; 18.3 ± 0.9 yrs; t = 1.7; p = 0.101) was also similar, but the majority of students who attended all course exams
were female (77.0%), whereas the majority of students who did not carry through were
male (59.3%) (chi2 = 11.8; p = 0.001). Average GPA in the last year of secondary school was higher in students
who carried through all course exams during the first year of university (68.6 ± 7.5%;
n = 42) in comparison to those who did not (63.6 ± 6.3%; n = 14; t = -2.2; p = 0.030). Students who did not attend all course exams showed a significantly higher
increase in WC (1.2 ± 2.2 vs. -0.0 ± 2.3; t = 2.4; p = 0.020) during the first semester. Regarding eating habits, only French fries consumption
was slightly but significantly higher in students who did not attend all course exams
(0.14 ± 0.11 #/week; 0.09 ± 0.08 #/week; t = 2.2; p = 0.028). No significant differences were found in physical activity, sedentary behaviour,
alcohol consumption, sleeping habits and stress levels between both groups.

Correlates of GPA

Descriptive statistics of all items tested as possible correlates of first year GPA
at university are shown in Table 1.

Results of the univariate regression analyses (see Table 2) indicated that female students and students who had higher GPA’s in the last year
of secondary school showed higher GPA’s in their first year at university. Weight
gain was negatively correlated with academic performance, i.e. the more students had
gained weight during the first semester at university, the lower their first year
GPA’s. Similar negative correlations were found for increase in BMI and WC. Students
who engaged more in gaming activities on weekdays seemed to score lower grades as
well. Regarding eating behaviour, lower academic performance was found when students
reported being on a diet, eating more frequently at the student restaurant, consumed
more soda or French fries, or reported more weekly alcohol use. Computer activities
on weekend days showed a negative trend (p < 0.1) towards significance.

Table 2.Correlates of GPA in first year university students (t-values, β-values and Adjusted
R2, n = 74)

Before running the multivariate model we checked for multicollinearity and excluded
weight change and BMI change which both showed r > 0.5 with WC change. As WC change showed the strongest correlation with the dependent
variable, this variable was included in the multivariate model. In addition, we decided
to exclude secondary school GPA as well because of the limited sample size (n = 42).
After inclusion of all remaining significant univariate variables, 30% of total variance
in academic performance was explained by the multivariate regression model. In this
multivariate model, only dieting status and frequency of alcohol use remained significant.
Eating at the student restaurant and soda consumption showed negative trends towards
significance (p < 0.1).

Discussion

The purpose of this study was to examine differences in socio-demographics and health
behaviour between Belgian (European) first year university students who attended all
final course exams and those who did not, as well as to identify weight and health
behaviour related correlates of academic performance in those students who attended
all course exams. Results indicated that female students showed higher GPA’s in the
first year at university. Furthermore, increases in (over) weight over the first semester,
sedentary behaviours, unhealthy eating and drinking behaviours negatively predicted
academic performance.

In agreement with findings of previous US studies [3,6,7,21], female college or university students tended to have higher grades than male students.
This could be partly explained by the fact that women more often show motivation,
discipline and time management skills that are important to perform well in higher
education [28,29]. Moreover, the study of Sheard et al. [29] revealed that female university students also reported a significantly higher mean
score on commitment compared to male students, whilst commitment was the most important
positive correlate of academic grades. The latter increases the likelihood of female
university students achieving higher grades than their male counterparts [28]. Furthermore, we observed the same trend when comparing students who attended all
course exams with those who did not, i.e. the majority of students who did not attend
all course exams during the first year at university were male. Similar to previous
findings in the literature [4-6] GPA in the last year of secondary school predicted first year university GPA positively.

Increases in weight, BMI and WC over the first semester period were related to lower
academic performance. Additionally, students who did not attend all course exams during
the first year of university showed a significantly higher increase in WC during the
first semester than those who attended all final course exams. Since no literature
on this matter was available, no comparison could be made. However, these results
indicated that increases in weight, BMI and WC may have affected students’ cognitive
performances. It might also be that students who lacked discipline to maintain weight
were equally not disciplined to perform well academically. Furthermore, it has been
shown that medically defined overweight status is negatively associated with academic
achievement [30,31].

Similar to other studies conducted in US university students [3,4], our results indicated that physical activity was not related to academic performance.
This finding is in contrast with the review study of Singh et al. [22] relating physical activity with academic performance in children and adolescents.
This latter study found strong evidence of a significant positive relationship between
physical activity and academic performance. According to Hillman et al. [8] regular participation in physical activity is linked to enhancement of brain function
and cognition, and thus positively influencing academic performance. In Singh et al.
[22], several hypothesized physiological mechanisms (e.g. increased blood and oxygen flow
to the brain and increased levels of endocrine processes) explaining the beneficial
effect of exercise on cognition are given. In addition, regular participation in sport
activities may improve students’ classroom behaviour and concentration during the
lessons [22]. Therefore, we could expect that students who were more engaged in physical activities
would perform better academically. However, on the other hand, when spending more
time exercising, students possibly tended to spend less time on their academic work,
so this might have offset the beneficial effects of physical activity on GPA at university.

Regarding sedentary behaviour, gaming on weekdays negatively predicted GPA. In addition,
computer activities on weekend days showed a trend towards significance (p < 0.1). This suggests a negative influence of ‘screen activities’ on grade points
in university students. Earlier research showed that the amount of time a university
student spends playing video games is negatively related with GPA [17]. Similar to physical activity, this negative relationship might be explained by the
fact that university students who spent more time playing videogames tended to spend
less time studying. However, in this study, the amount of reading (incl. leisure time
reading) and studying during the whole week did not correlate significantly with GPA.
In contrast to the literature [19], the amount of sleep was not associated with academic performance.

Students who were on a diet, ate more in the student restaurant, consumed more (sugar
containing or diet) sodas or ate French fries more frequently tended to have lower
GPA’s. Similar results have been found in adolescents showing that unhealthy food
choices (including fast foods) were negatively related, whereas fruit and vegetable
consumption was positively related to secondary school end-of-year achievement [13,15]. In addition, Florence et al. [32] concluded that 10 year old students with decreased overall diet quality were more
likely to perform poorly on an assessment used as a measure for academic performance.
Moreover, dietary adequacy, variety, fruit and vegetable consumption and dietary fat
intake were demonstrated as being important to academic performance [32]. Concerning the association between GPA and eating at the student restaurant, it
could be that university students tend to make more unhealthy choices (e.g. more fatty
foods and less fruit and vegetables) when eating in the campus restaurant. When controlled
for other significant variables, being on a diet remained significant in the multivariate
model. No previous correlational studies have assessed dieting status so far. These
results suggest that unhealthy eating behaviours are related to lower academic performance.

Finally, even when controlled for other significant variables, frequency of alcohol
use was associated with academic performance. The more frequent students drank alcohol,
the lower their academic grades at the end of their first year at university. The
latter confirmed the findings of Singleton et al. [5] showing a similar negative correlation between alcohol consumption and GPA in US
university students. Furthermore, in a Belgian study, a 25% excess risk of failing
at university was found in first year students who met alcohol dependence criteria
[18].

According to our results many weight and health-related behaviours were associated
with university students’ academic performance, with dieting status and alcohol use
emerging as the strongest correlates of academic performance, once controlled for
other significant variables. However, we should be careful interpreting these results.
In a review and meta-analysis of Richardson et al. [21], several psychological correlates of university students’ academic performance were
reported. Self-esteem, academic intrinsic motivation, and academic and performance
self-efficacy were positively associated with GPA [21]. Goal commitment and social support showed a positive relation with GPA, whereas
measures of psychological health (general and academic stress) were negatively correlated
with academic achievement [21]. In addition, Chambel et al. [33] indicated that higher levels of academic satisfaction [33] influence student performance positively. Taking this into account, underlying psychological/motivational
mechanisms might be mediating or confounding these relationships. Typically, a mediator
is a third variable affecting the relation between two other variables [34]. E.g. previous research of Kristjansson et al. [14,15] in secondary school adolescents indicated a weak mediating role of both self-esteem
and school contentment (satisfaction) on the relation between health behaviours and
academic grades. A confounder, on the other hand, causes both the independent and
the dependent variable [34]. It might also be that students who were more disciplined concerning their health
behaviour, showed the same discipline regarding academic performance. E.g. lack of
self-discipline might cause students to eat more unhealthy foods, and at the same
time, it might cause these students to perform worse academically. A study of Duckworth
et al. [35] showed that self-discipline accounted for more than twice as much variance as IQ
in final grades in adolescents. Therefore, future studies should investigate possible
mediation and/or confounder effects of psychological/motivational aspects on the relation
between health behaviour and academic performance in university students.

A first strength of this study is that we were able to regress academic performance
onto objectively measured first semester changes in weight, BMI, fat% and WC. Secondly,
in contrast to other studies, we used objective GPA’s (obtained from official university
records) instead of self-reports. However, this study has some limitations as well.
Firstly, it should be mentioned that no information was collected to verify whether
those who did not carry through did so for academic reasons, or reasons related to
health. Therefore, it might be that students who did not attend all course exams did
not automatically lack self-discipline or academic competences, but were forced to
miss out on exams due to health related reasons. Secondly, since our health-related
questionnaire was only completed at follow-up, we were not able to regress academic
performance onto changes in physical activity, dietary habits, and other health behaviours
over time. Thirdly, because of the limited sample size (n = 42) we chose to exclude
secondary school GPA from the t-tests as well as from the multivariate regression
model to ensure sufficient degrees of freedom. Subsequently, we did not control our
multivariate regression model for secondary school GPA. Fourthly, we have to be aware
that the use of objective measures of physical activity (e.g. accelerometers) and
food frequency questionnaires or food diaries would have given us more accurate and
detailed information on physical activity and dietary behaviour. Finally, due to a
relatively small sample size with a slightly different mean age and gender distribution
in comparison to all freshmen, we have to be cautious with generalizing these results
to the entire student population.

Conclusions

This is the first European study showing associations between a wide range of weight
and health related behaviours and academic performance in first year university students.
Students who did not attend all course exams were predominantly male, showed higher
increases in WC during the first semester and consumed more French fries than those
who carried through and attended all final course exams. Furthermore, gender, secondary
school GPA, changes in weight, BMI and WC, gaming, dieting status, eating at the student
restaurant, soda and French fries consumption, and alcohol consumption during the
academic year were associated with end-of-year GPA in first year university students
who attended all course exams. Future intervention studies aiming to improve students’
academic performances should pay special attention to male students with lower secondary
school grades showing increases in weight, BMI and WC over the first semester, higher
levels of sedentary behaviour and unhealthy eating and drinking habits. However, it
remains to be investigated whether interventions aiming at promoting healthy behaviours
among university students could indeed have a positive impact on academic performance.

Competing interests

The authors declare that they have no competing interest.

Authors’ contributions

TD participated in the design of the study, collected all data, performed the data
analyses and drafted the manuscript. IDB participated in the design of the study and
revised the manuscript critically. BD and PC participated in the design of the study,
contributed to the interpretation of data and revised the manuscript critically. All
authors read and approved the final manuscript.

Acknowledgements

The authors thank all students participating in this study. Special thanks to Linde
Van Hecke, Tine De Greef and Joke Paridaens for their contribution in data collection.

References

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